I love this question! I’m gonna focus on simple.
- Simply move your CSS’
link elements to as close to the top of the HTML document as you can. Seriously, it can make a difference. I did an audit for a company once and their CSS was linked on like line 81 of their HTML; this meant that touch icons, Facebook/Twitter card images, plugins’ JS, etc. were all being requested before their render-blocking CSS was. By moving the CSS up to line ~5 we managed to improve render time by a good half second.
- Don’t put scripts at the bottom any more: make use of
async and defer attributes
- Make use of resource hints[1] to tell the browser to prioritise things out of regular order (or for subsequent navigation).
All of these are one-line (or less) fixes.
- https://www.w3.org/TR/resource-hints/